Remote control isotope manipulator



swan Room OR ammw {mm FOR wussme COPY April 30, 1963' F. SCHOUTEN REMOTE CONTROL ISOTOPE MANlPULATOR 2 Sheets-Sheet 1 Filed Aug. 15, 1961 INVENTOR Frank Schau/en Mia/A. ATTORNEY F. SCHOUTEN REMOTE CONTROL ISOTOPE MANIPULATOR April 30; 1963' 2 Sheets-Sheet 2 Filed Aug. 15, 196].

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- Unite tates atent REMOTE CONTROL ISGTOPE MANIPULATOR Frank Schoutcn, Glcnnrm, Md, assignor to the United States of America as reprlsented by the Secretary of the Army Filed Aug. 15, 1961, Scr. No. 131,692 2 Claims. (Cl. 214-1) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a portable field device for lifting a high-intensity gamma radiation source from its shield (steel-jacketed lead cylinders) without exposing the personnel involved to harmful radiation.

The principal object of this invention is that the device raises the radioactive source inside of a tube from its steel-jacketed lead shield to a preselected position by air pressure supplied by an air compressor. The source remains suspended in said tube in a floating state from where a desired exposure of the gamma emitting rays from the radioactive source may be acquired until power to said air compressor is turned off. The latter feature is particularly important where safety is concerned since in case of failure of the air compressor, the radioactive source will immediately, by way of gravity, fall back into its steel-jacketed lead shield or it can be knocked down into said shield through means of a source stop, thus entirely eliminating the danger of harmful radiation.

Another object of the invuntion is that if ground level tests are desired, the shield can be alternately operated through a tilting means thus permitting the device to be utilized in still another capacity.

Still another. object of the invention is that it has a means through which (from a substantially long distance) it may be remotely contro led and manipulated in any desired position. This feature affording stilla further safety precaution from harmful radiation.

Other objects and features of the invention will be apparent from the following description and claims taken in connection with the accompanying drawings.

'In order to study the shielding that, for example, a concrete structure affords ag inst gamma radiation, a device such as herein described was needed to produce a plain.

isotopic source of gamma radiation. In a previous method the time required to construct this plane source resulted in personnel being exposed to significant doses of radiation since the source was laid out manually in a grid pat tern. Tests proved that only 1 field of relatively low radiation could be conducted under these former circumstances and therefore it was impossible to study gamma-ray penetrations adequately. Through the use of the present device of remotely lifting the radioactive source from its shield and thereby holding same for any desired length of time, it is possible to produce a radiation field of much higher intensity without ever exposing personnel conducting the tests to hazardous radiation.

In the drawings:

FIG. 1 is a plan view of the invention showing the manipulating structures.

P16. 2 is a side elevation of'the invention showin the manipulating structures.

FIG. 3 is a partial view of an air-lift system.

FIG. 4 is an end view of the invention showing the tilting mechanism.

Fl( 5 is a sectionalized fragmentary view of the airlift system.

FIG. 6 is a section of a riser tube. FlG. 7 is a view taken on line 77 of FIG. 5 showmg the radial channels o the riser tubc lower end cap.

' FIG. 8 is a section taken through section 88 of FIG. 6 showing relief slots.

The device consists of a cylindrical steel-jacketed lead shield 1 resting through means of leveling lugs 3 and screws 5 on a metal platform 7 as shown in FIG. 2. The shield also may alternately rest on said platform through means of a metal basket or carrier 9 supported on trunnions 10 and support columns 11, 12 as shown in FIG. 4. The alternate adaptation is generally used with a tilting means. The shield 1 at the top has carriage lugs 13, 15, lock bar lugs 17, 19, and a centrally located cavity (not shown) for storing the radioactive source 21.

The apparatus is so designed, that in certain situations, the shield may be through means of'a quadrant gear 23 and a reversible electric motor 25 (see FIG. 4) tilted sufficiently enough so that a ground level test may be adequately conducted.

Referring now to FIG. 2, there is rotatably mounted a metal tubular column 27 on the platform 7 and fixed limit screws 28, 30. The column 27 has near its base a pair of integral arms 29, 31 with pull-cords 33, 35. At its upper end it has a bracket 36 and an integral arm unit 37, radially extending pulley arms 39, 41 and 43. Through means of the pulley arms 39, 41 and a set of pulleys with pull-cords 45', 47, there is suspended from ears 44, 46 an air-lift system shown at 49. Through means of the arm 43 and a set of pulleys with a pull-cord 50, there is suspended from car 51 a plug shown at 53. The plug comprising a conical lead body 52 having said ear 51, stainless steel conical jacket 54 and a sponge rubber rain shield 55. The pull-cords 45, 47 at a relatively short distance from their respective pulleys are joined together forming a single pull-cord 56. The pull-cords 56 and pass downwardly through and out below the base of tubular column 27 where they both engage a dual pulley 57.

Mounted on the platform 7 and located next to the tubular column 27, there is a mount 59. This mount serves as a support for a plurality of operating units of the device. The units consist of an air pressure line 61, whistle 63, air pressure regulator 65, gauge67, air pressure valve 69, and a rubber hose 71. The whistle 63 and the air pressure valve 69 have pull-cords 73, 75. These, at a relatively short distance, are joined together forming a single pull-cord 77. The joining of these pullcords is done in order that their respective units can be simultaneously operated.

The air hose 71 which in a sense is the air-lifeline to said air-lift system, is firmly connected into the head 78 of a cylindrical Plexiglas or aluminum retainer tube 79. Concentrically located within the retainer tube 79 there is a cylindrical Plexiglas or aluminum riser tube 81. At the inlet of hose 71, said riser tube has a shoulder 83 or a stepdown to somewhat reduced diameter. At thispoint, both the retainer and the riser tubes are firmly welded to each other creating an annular channel 85. The latter extends downwardly where it is continued through means of stainless steel cylindrical retainer and riser extensions 87 and S9. The lower end of said extension 87 is closed off with a stainless steel end cap 91 having radial channels 93. The radial channels, which can be round, square, or triangular whichever is most convenient, are adapted to air-communicate with the channel and the inlet of hose 71. Centrally located within the cap 91 there is a sponge rubber cushion 85 supporting the radioactive source 21. At the upper end the retainer extension 87 has a stainless steel round flange 99, this is fastened on to a stainless steel conical jacket 101. The jacket at its upper end is in turn rigidly fnstenedonto the shield 1.

it is to be 'noted here that the subsequent parts, extensions 87, 39, cap 91, flange 99 and the jacket 101 are permanently embedded in the interior lead mass (not shown) of the shield 1. The retainer tube 79 is pressfitted into a stainless steel conical body 103. This body and the plug shown at 53 are constructed in such a manner that at assembly they will snugly fit inside of the jacket 101. At the lower end, the tube 79 has a frictionheld sponge rubber cushion 105, while at the upper end it has a friction-held sponge rubber rain shield 107. Extending upwardly and located approximately 36 inches from the head of the retainer tube 79, the riser tube 81 has relief slots 109. lnteriorly located it also has a cylindrical slideable Plexiglas or aluminum source stop 1 11. The latter having in its hollow center press-fitted a lead slug 113 containing a pull-cord 115, which is fastened onto the bracket 36.

The tube 81 at its top is closed with a metal end cap 117 having an oversized hole 119. During transportation, the radioactive source 21 is retained or locked in inside of the shield 1, through means of the plug shown at 53, lock bar 121 and padlock 123. Having the hose 71 and all the pull-cords properly connected to their respective parts, the operator removes from the shield 1 the padlock 123 and the lock bar 121 freeing the plug at 53. The pull-cord 50 is fastened onto said plug through ear 51. Upon pulling (generally from distance) the cord 50, the plug is completely raised from the cavity of the shield 1. Through means of manipulation of pull-cords 33, 35 and the laterally operating arms 39, 31, the operator positions over the plug vacated cavity, the air-lift system shown at 49. The latter is lowered into said cavity through slackening of pull-cord 56, thus readying the device for the initial test.

It is to be noted at this point that the lateral move- "ment of arms 29, 31 is fixed or limited according to the seating positions of the plug and air-lift system through means of the fixed limit screws 28, 30. For example, the operator, having the plug and the air-lift system in raised position, can by fully pulling the cord 33 move said plug directly over the cavity in the shield 1. The arm 31 comes to an automatic stop against limit screw 30. Likewise, by pulling the cord 35, the operator will bring over the air-lift system in a direct alignment with said cavity, since the arm 29 abuts with limit screw 28.

To lift the radioactive source from the shield 1, power is applied to an air compressor (not shown) which produces an air flow of c.f.m. at p.s.i.g. By pulling cord 77 which operates the whistle 63 and the pressure valve 69, air is forced through the hose '71 downwardly via annular channel 35, radial channels 93, under the source 21, and into the riser tube 81. Since the bore diameter of the latter is only about 5% greater than the diameter of the source 21, the source is slidingly pushed upward, the air escaping through relief slots 109, until it reaches the'source stop 11. The source stop is suspended inside of the tube 81 through means of the cord and the bracket 44. The radioactive source 21 remains suspended in a floating state in the tube 81, until the air compressor is turned off, or goes off in 56 Of a general power failure. In both cases the source '21 will by wayof gravity fall back, or it can be knocked down back, through meansof cord 115 and source stop 111 into the shield 1. The whistle 63 is an additional safety measure of the device since, as long as there is maintained a steady air pressure throughout the system, the whistle will give out a constant signal. Upon failure of the latter, the whistle will cease to operate, warning the personnel to take corrective actions.

The radioactive sources used were cobalt or cesium -barium Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A device for remotely removing a plug from a shield for a radioactive source and replacing it with an air driven riser tube assembly which comprises a shield with a plug therefor, means connected to said plug for rcmotely'raising said plug, an air driven riser tube assembly having a base that is interchangeable with said plug, means connected to said riser tube for remotely raising said riser :tube assembly, and means connected to said plug raising means and said riser tube assembly raising means for remotely moving said plug and riser tube assembly laterally.

2. A device for remotely removing a plug from a shield for a radioactive source and replacing it with an air driven riser tube assembly which comprises a shield, a base for the shield, a plug for the shield, an air driven riser tube assembly, a vertical column rotatably mounted on said base having pulley arms adapted to orcrlic said plug, means connected .to said column to remotely rotate same a predetermined amount, means connected to said plug and said riser tube assembly to remotely raise same as required.

References Cited in the tile 01 this patent UNITED STATES PATENTS 1,638,009 Cambessedes Aug. 9. 1927 2,514,909 Strickland July H, 1950 2,811,267 Bock Oct 2). 1957 54 Coste lo July 15, 1953 2,965,761 Horvath D c. 30, 1960 

1. A DEVICE FOR REMOTELY REMOVING A PLUG FROM A SHIELD FOR A RADIOACTIVE SOURCE AND REPLACING IT WITH AN AIR DRIVEN RISER TUBE ASSEMBLY WHICH COMPRISES A SHIELD WITH A PLUG THEREFOR, MEANS CONNECTED TO SAID PLUG FOR REMOTELY RAISING SAID PLUG, AN AIR DRIVEN RISER TUBE ASSEMBLY HAVING A BASE THAT IS INTERCHANGEABLE WITH SAID PLUG, MEANS CONNECTED TO SAID RISER TUBE FOR REMOTELY RAISING SAID RISER TUBE ASSEMBLY, AND MEANS CONNECTED TO SAID PLUG RAISING MEANS AND SAID RISER TUBE ASSEMBLY RAISING MEANS FOR REMOTELY MOVING SAID PLUG AND RISER TUBE ASSEMBLY LATERALLY. 